Stainless Steel321 Spool

Manufacturer, Supplier & Exporter of Stainless Steel321 Spool

Stainless Steel 321 Spool is an austenitic, titanium-stabilized grade of stainless steel designed to offer excellent resistance to intergranular corrosion, especially in high-temperature environments. This stabilization prevents carbide precipitation during welding and heat exposure, making SS 321 spools ideal for applications involving frequent temperature fluctuations or continuous exposure to temperatures up to 900°C. Due to their exceptional thermal stability, oxidation resistance, and mechanical strength, SS 321 spools are widely used in petrochemical pipelines, furnace systems, thermal processing plants, and high-temperature fluid distribution lines...

Riddhi Siddhi Impex is a well-known manufacturer, exporter, and domestic supplier of Stainless Steel 321 Spool assemblies in India. The company has built a strong reputation for delivering high-quality spools that meet strict international standards such as ASTM A312 and ASME SA312. Their advanced manufacturing unit is equipped with CNC bending machines, automated welding systems, and precision fabrication tools, ensuring every SS 321 spool is manufactured with high dimensional accuracy, smooth weld finishes, and excellent structural integrity..

Riddhi Siddhi Impex specializes in custom fabrication of Stainless Steel 321 spools, offering complete flexibility in spool length, diameter, wall thickness, fittings, flange connections, and bend configurations. Custom-built spool assemblies are designed to match exact customer requirements and installation layouts, making them ideal for EPC contractors, engineers, and industrial fabricators. Whether the requirement is for single-line spools, complex multi-section assemblies, or fully integrated pipelines, the company provides tailor-made solutions with a guarantee of durability and performance...

To ensure top-notch reliability, each Stainless Steel 321 Spool undergoes rigorous quality checks and testing procedures. These include PMI testing, weld penetration checks, hydrostatic testing, non-destructive testing (NDT), radiographic testing (RT), ultrasonic testing (UT), hardness tests, and dimensional accuracy inspections. With a strict quality assurance system in place, Riddhi Siddhi Impex ensures that the delivered spools meet international mechanical and metallurgical standards. The company also provides EN 10204 3.1/3.2 test certificates to guarantee authenticity and traceability..

Stainless Steel 321 Spools offer several benefits over non-stabilized grades such as 304 and 316, especially in high-temperature applications. Titanium stabilization prevents sensitization and intergranular corrosion, significantly improving the performance of SS 321 in environments containing high levels of heat or corrosive chemicals. These spools are widely used in refinery pipelines, exhaust systems, heat exchangers, power plant condensers, chemical transfer lines, and thermal oxidizers. Their superior creep strength and oxidation resistance help maintain structural integrity even under continuous thermal cycling..

Stainless Steel 321 Spool Specification

Product Name	Stainless Steel 321 Spool
Manufacturer	Riddhi Siddhi Impex
Material	Stainless Steel 321 (Austenitic, Titanium Stabilized)
Standard	ASTM A312 / ASME SA312
Size Range	DN15 to DN600 (1/2" to 24")
Wall Thickness	Sch 5 to Sch 160
Length	Custom as per requirement
End Connection	Butt Welded, Flanged, Threaded
Applications	Petrochemical, Thermal, Power Plants, Refineries, Chemical Industry

Chemical Composition (%)

Element	Content (%)
Carbon (C)	0.08 Max
Manganese (Mn)	2.00 Max
Phosphorus (P)	0.045 Max
Sulfur (S)	0.03 Max
Silicon (Si)	1.00 Max
Nickel (Ni)	9.0 – 13.0
Chromium (Cr)	17.0 – 19.0
Titanium (Ti)	5×C min – 0.70 Max

Mechanical Properties

Property	Value
Tensile Strength	515 MPa Min
Yield Strength (0.2% offset)	205 MPa Min
Elongation	40% Min
Hardness	≤ 95 HRB
Impact Strength	Excellent at elevated temperature

Nominal Dimension Chart

Nominal Size (NB)	Outside Diameter (mm)	Wall Thickness (mm)
1/2"	21.3	2.77
1"	33.4	3.38
2"	60.3	3.91
4"	114.3	6.02
6"	168.3	7.11
8"	219.1	8.18
12"	323.9	12.7

Equivalent Grades

Standard	Grade
ASTM	A312 TP321 / TP321H
EN	1.4541
JIS	SUS321
DIN	1.4541

Equivalent Standards

Standard	Description
ASTM A312	Seamless, Welded, and Heat-Exchanger Tubes of Stainless Steel
ASME SA312	Specification for Seamless and Welded Stainless Steel Pipes
EN 10216-5	Seamless Stainless Steel Tubes for Pressure Purposes

Other Types of Stainless Steel Spools

Type	Description
SS304 Spool	Austenitic stainless steel for moderate temperature and corrosion applications
SS316L Spool	Low-carbon austenitic stainless steel with superior corrosion resistance
SS317L Spool	High alloy stainless steel for strong chemical resistance
SS321H Spool	High-temperature stabilized variant of SS321 for extreme thermal conditions

As a leading Stainless Steel 321 Spool Domestic Supplier, Riddhi Siddhi Impex supplies its premium-quality spools across major industrial and metro cities in India. Their domestic supply network covers Mumbai, Delhi, Bengaluru (Bangalore), Hyderabad, Chennai, Kolkata, Pune, Ahmedabad, Surat, Vadodara, Rajkot, Nagpur, Indore, Bhopal, Jaipur, Kanpur, Lucknow, Agra, Varanasi, Amritsar, Chandigarh, Mysuru (Mysore), Udaipur, Jodhpur, Visakhapatnam, Coimbatore, Madurai, Kochi, Thiruvananthapuram, Mangalore, Nashik, Kolhapur, Chandrapur, Akola, Vilayat, Somnath, Dahej, Ankleshwar, Navsari, Valsad, Narmada, and Rajpipla. This extensive supply chain ensures timely deliveries to project sites and industries across the country..

Frequently Asked Questions (FAQs)

Q1: What are the main applications of Stainless Steel 321 Spool?

A1: Stainless Steel 321 Spools are mainly used in high-temperature chemical processing, refineries, power plants, thermal systems, and heat exchangers.

Q2: Can Riddhi Siddhi Impex provide customized spool sizes?

A2: Yes, we manufacture custom spool assemblies in various diameters, wall thicknesses, lengths, and end connections to meet project-specific requirements.

Q3: What makes SS321 better than SS304 at high temperatures?

A3: SS321 is titanium-stabilized, which prevents intergranular corrosion and carbide precipitation at high temperatures, making it superior for thermal applications compared to SS304.

Q4: Which Indian cities can Riddhi Siddhi Impex supply SS321 spools to?

A4: We supply across major cities including Mumbai, Delhi, Bengaluru, Hyderabad, Chennai, Kolkata, Pune, Ahmedabad, Surat, Vadodara, Rajkot, Nagpur, Indore, Bhopal, Jaipur, Kanpur, Lucknow, Agra, Varanasi, Amritsar, Chandigarh, Mysuru, Udaipur, Jodhpur, Visakhapatnam, Coimbatore, Madurai, Kochi, Thiruvananthapuram, Mangalore, Nashik, Kolhapur, Chandrapur, Akola, Vilayat, Somnath, Dahej, Ankleshwar, Navsari, Valsad, Rajpipla, and Narmada.